Various power driven tools have been developed for tightly wrapping electric conductor about electrical terminals to form mechanical, solderless electrical connections. Tools of this type generally include a rotary bit of hollow construction with a longitudinal recess therein for receiving the wire. The bit is selectively driven by a suitable motor and drive train housed within a case held by the operator of the tool. Some form of finger-operated switch is usually provided on the case for controlling the tool. Before the bit is positioned over the terminal, wire is inserted into the recess of the bit. The tool is actuated for a short interval to accomplish connection. Most of the conductor wrapping tools now in use also include an indexing mechanism which stops the bit in a predetermined angular orientation to facilitate positioning of the tool for the next wrapping cycle. Conductor wrapping tools are thus characterized by high speed operation over short intervals followed by abrupt stoppage on a repeated basis, a combination which presents considerable design and engineering problems.
The prior tools have been generally large and heavy, in addition to being noisy and costly. Size and weight, of course, are wearisome to an operator, while noise affects the operator productivity. Although prior electric conductor wrapping tools have not been unreliable as a whole, relatively frequent maintenance of a time-consuming and thus costly nature has been required to achieve satisfactory reliability.
The drive train of an electric conductor wrapping tool is one area in which especially severe wear occurs. Aside from intermittent operation of the motor, abrupt stoppage of the drive train to index the rotary bit can cause damage to the motor or its mounting and to the drive train components. It is thus desirable to provide for gradual arrest of the motor and drive train after indexing of the bit, however, the tools of the prior art which have included structure for this purpose have been unduly complex and inadquately controllable. Finally, those prior tools which can be used with more than one type of bit are capable of accommodating only a narrow range of bits. A need has thus arisen for a new and improved conductor wrapping tool.